This section introduces aspects that may be helpful in facilitating a better understanding of the invention. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art. Several technical terms and/or phrases will be used throughout this application and merit a brief explanation. The 3rd Generation Partnership Project (3GPP) attempts to create a uniform third-generation mobile phone system. 3GPP standards are called releases and different functionality is present in the different versions of the releases. The 3GPP standards continue to evolve and the major releases of the standards can be differentiated using supported features. It is required that a single release of the Policy and Charging Rules Function (PCRF) be used with different networks operating with different minor versions of the standards.
When a new session is established between two 3GPP nodes, e.g.: a PCRF node and a Gxx gateway, the initiating node indicates, in a session request, which 3GPP major release version should be used for the session. The receiving node is either capable of establishing the session under that major release version and replies as such, or if it is not capable, it replies with the next highest major release that under which it can establish the requested session. For example, a Gxx gateway might request a session under 3GPP major release 10 and a PCRF node might reply that it can establish the session under major release 8 or 9. The Gxx gateway would then send a message to the PCRF node indicating that the session should be established under major release 9. Some additional aspects of the prior art are discussed with reference to FIG. 2 below.
Although this exchange between the nodes only takes a few messages, it is highly desirable to have an improved system for negotiating releases during session establishment. for nodes handling a large volume of such messages, and when session establishment delay is undesirable, for example in the case of S9 roaming, it would be advantageous to have a faster and more efficient method of signaling negotiation of the major release on a session request.